Image forming apparatus using a developer with a solubility parameter

Abstract

An image forming apparatus includes an electrostatic latent image holding member, a charging device, a latent image forming device, a developing device that stores a liquid developer containing a toner and a non-volatile carrier liquid, and develops the electrostatic latent image formed on the surface of the electrostatic latent image holding member by the liquid developer to form a toner image, a transfer device that transfers the toner image onto a surface of an impermeable recording medium, and a fixing device, wherein when the SP value of the toner is set as SP(t), the SP value of the non-volatile carrier liquid is set as SP(c), and the SP value of the recording medium is set as SP(m), an absolute value of a difference between SP(t) and SP(c) is from 1.5 to 7.0 and the following relational expression (A) is satisfied: | SP ( c )− SP ( m )|>| SP ( t )− SP ( m )|.  Relational expression (A)

What is claimed is: 
     
       1. An image forming apparatus, comprising:
 an electrostatic latent image holding member; 
 a charging device that charges the surface of the electrostatic latent image holding member; 
 a latent image forming device that forms an electrostatic latent image on the surface of the electrostatic latent image holding member; 
 a developing device that stores a liquid developer containing a toner and a non-volatile carrier liquid, and develops the electrostatic latent image formed on the surface of the electrostatic latent image holding member by the liquid developer to form a toner image; 
 a transfer device that transfers the toner image onto a surface of an impermeable recording medium; and 
 a fixing device that heats and presses the toner image transferred to the surface of the recording medium and fixes the toner image to the recording medium, 
 wherein when the SP value of the toner is set as SP(t), the SP value of the non-volatile carrier liquid is set as SP(c), and the SP value of the recording medium is set as SP(m), an absolute value of a difference between SP(t) and SP(c) is from 1.5 to 7.0 and the following relational expression (A) is satisfied:
   | SP ( c )− SP ( m )|>| SP ( t )− SP ( m )|,  Relational expression (A):
 
 
 wherein a ration G′(65)/G′(90) of a storage elastic modulus at 65° G′(65) to a storage elastic modulus at 90° G′(90) in the toner is from 1×10 1  to 1×10 3 . 
 
     
     
       2. The image forming apparatus according to claim wherein the non-volatile carrier liquid contains dimethyl silicone. 
     
     
       3. The image forming apparatus according to  claim 1 ,
 wherein the fixing device comprises:
 a first heating device that heats the toner image in a non-contact manner up to a temperature equal to or higher than a melting temperature of the toner; and 
 a second heating and pressing device that heats the toner image while pressing the toner image at a temperature equal to or higher than the melting temperature of the toner after the heating performed by the first heating device. 
 
 
     
     
       4. The image forming apparatus according to  claim 3 ,
 wherein the second heating and pressing device comprises:
 a heating and pressing roll that heats the toner image while pressing the toner image; and 
 a carrier liquid removing member that removes the non-volatile carrier liquid attached to the heating and pressing roll. 
 
 
     
     
       5. An image forming method, comprising:
 charging a surface of an electrostatic latent image holding member; 
 forming an electrostatic latent image on the surface of the electrostatic latent image holding member; 
 developing the electrostatic latent image formed on the surface of the electrostatic latent image holding member by a liquid developer containing a toner and a non-volatile carrier liquid to form a toner image; 
 transferring the toner image to a surface of an impermeable recording medium; and 
 fixing the toner to the recording medium by heating and pressing the toner image transferred to the surface of the recording medium, 
 wherein when the SP value of the toner is set as SP(t), the SP value of the non-volatile carrier liquid is set as SP(c), and the SP value of the recording medium is set as SP(m), an absolute value of a difference between SP(t) and SP(c) is from 1.5 to 7.0 and the following relational expression (A) is satisfied:
   | SP ( c )− SP ( m )|>| SP ( t )− SP ( m )|,  Relational expression (A):
 
 
 wherein a ratio G′(65)/G′(90) of a storage elastic modulus at 65° G′(65) to a storage elastic modulus at 90° G′(90) in the toner is from 10 1  to 1×10 3 . 
 
     
     
       6. The image forming method according to  claim 5 , wherein the non-volatile carrier liquid contains dimethyl silicone. 
     
     
       7. The image forming method according to  claim 5 ,
 wherein the fixing includes:
 firstly heating the toner image in a non-contact manner up to a temperature equal to or higher than a melting temperature of the toner; and 
 secondly heating the toner image while pressing the toner image at a temperature equal to or higher than the melting temperature of the toner after the heating performed in the firstly heating. 
 
 
     
     
       8. The image forming method according to  claim 7 ,
 wherein the secondly heating is performed by a heating and pressing device including a heating and pressing roll that heats the toner image while pressing the toner image and a carrier liquid removing member that removes the non-volatile carrier liquid attached to the heating and pressing roll. 
 
     
     
       9. The image forming method according to  claim 7 , wherein the non-volatile carrier liquid contains dimethyl silicone.